1. Field of the Invention
The present invention relates to an electromechanical transducer which generates mechanical drive force by applying voltage and an electromechanical transducer driving method, for example, to an electrostatic actuator which is driven by electrostatic force and an electrostatic actuator driving method.
2. Description of the Related Art
Recently the electrostatic actuator is often used in order to drive a lens mounted on a digital camera, a cellular phone, and the like to perform zooming operation or autofocus operation (Jpn. Pat. Appln. KOKAI Publication Nos. 6-277894 and 9-46654). In an actuator control unit in which such an electrostatic actuator is operated, a dedicated operation module for each type of device in which an operation sequence is stored is previously incorporated, the lens is driven in accordance with the previously stored operation sequence on the basis of an external signal generated by the zooming operation of a user or the like.
In addition to the electrostatic actuator, the electromechanical transducer such as a piezoelectric actuator is well known as the device which generates the mechanical drive force by applying the voltage (Jpn. Pat. Appln. KOKAI Publication Nos. 2001-119917 and 2002-27767).
There is the following problem in the electrostatic actuator and the electrostatic actuator driving method. Namely, since the dedicated operation module is produced for each type of device, production cost per one electrostatic actuator is increased, which eventually increases the production cost of the portable devices such as the cellular phone and the digital camera into which the electrostatic actuator is incorporated.